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ARCHIVED FORUM -- March 2012 to February 2022
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This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022

 

BM4400 Basket Case

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This post has 98 Replies | 2 Followers

Craig
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Martin...unfortunately I had picked up on this crossover, OIC100/101 are BCE and OIC102/102 are BEC. Checked them out non the less and all is well, however as an aside as I was re testing TR115 I noticed what I suspect is the rougue diode which doesn't appear on the schematic....looks like D106 and is connected from the collector of TR115, on the solder side, to the collector of OIC100....see below pictures.

Craig
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marked up schematic......

Craig
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oops....sack the above, it's actually the emitter of 0IC100 and the collector of 0IC101

Craig
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Craig replied on Sun, Jan 29 2017 6:20 PM

Well......following the removal ant testing of all the transistors and diodes in what was a monumental push I still couldn't find a failed component! in despair I powered up and was delighted to see the fault relay idle....connecting up a speaker to both channels and selecting FM I was rewarded with a crisp and clear signal from both speakers.......I don't know which component was giving me all this grief, dry joint or open circuit, but clearly (as Martin predicted) it was something of the that order, Martin......your a star, your support is invaluable.

Still got a bit to do...set up the quiet quiescent current.....box it all up and sit back for a good listen ;¬)

Craig
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Picture of the repair to the cracked track on the solder side, will be epoxy fixing a piece of old circuit board (if I can find a bit) on the top side to add mechanical strenth to the repair, not a very sharp image i'm afraid.

Craig
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Set the quiet current to the prescribed 5.6mV........

Craig
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fitted a support over the cracked section of PCB with the help of epoxy glue, not sure how the boys ad Dell would view the destruction of one of their graphic cards....but hey...needs must when the devil drives ;¬)

marc
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marc replied on Mon, Jan 30 2017 8:13 PM

That piece of graphic card is in a better place now!

priklep
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priklep replied on Mon, Jan 30 2017 9:07 PM

Dear Craig,

I am  constantly watching your progress with interest . I have no electrical skills, so it is for me this is Confused. Do no give up, new BM wooden cabinet is beautiful. I am listening my BM4400 now, it is worth  to do it.

ALF
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ALF replied on Tue, Jan 31 2017 1:41 AM

I just had my last delivery from RS !!

Never again - delayed deliveries, faulty parts, parts missing, charged premiun prices......for what ?

Spending $$$ dialing 1300xxxx numbers.......no thanks :-):-)

ALF

beo3000
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beo3000 replied on Tue, Jan 31 2017 12:35 PM

RS must be different in Australia in the UK they are very good especially if you only want couple of pound worth of stuff as its all free next day delivery 

some things are cheaper there as well altho a lot is more expensive.

Craig
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Pretty much at the end game now.....refitting the screen inside the top cover...... 

Craig
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Closed up and back in service....you all know how good these sound, I'm not entirely convinced about the finish.....it looks so much different from the norm that is bordering on strange, none the less it's been an entertaining journey......

Craig
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Couldn't get rid if the ding in the front after all...........

Craig
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I also need to address a minor issue with one of the retaining machine screws at the rear.....the thread is stripped and will need to be tapped out oversize and a new screw fitting 

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Craig
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last one....

beo3000
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beo3000 replied on Tue, Jan 31 2017 8:01 PM

looks great now you need to find a beogram with a scruffy plinth and make one to match 

Saint Beogrowler
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I've been looking forward to these pictures for a while! I think it looks great but maybe it would look even better on Beomaster 4000 with the dark face to contrast...

Hmmm.

What kind of veneer do you think you will try for your next basket case?
ALF
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ALF replied on Thu, Feb 2 2017 5:38 AM

That may well be the case in the UK :-):-) lucky you !!

I waited for some wire-wound resistors for over 2 weeks only to find out during the wait they were actually coming from their uk-warehouse:-)

And then their policy of selling 10 or 25 parts if you only require 2.......yes, that is not always the case

But more often than not.

So, I definitely said 'good bye' to RS.

ALF 

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